Lapping, please explain for a euro guy
 

Ok, so I'm rebuilding my engine and luckily I found the plates to have little wear.

No problem to have them 'reworked'.
Now, I read a lot on this board and 'lapping' is always coming up about this.

I know how a normal cilinder head is being reworked or dropeed and with what machine. Last time I was at the local engine shop I tried to explain what I was looking for.

They told me that stone grinding is about the smoothest way to do this.

Can anyone please explain (maybe even with some pictures) how 'lapping' is being done, with what kind of machine and how much material can be taken away in order to maintain a sufficient layer of hardened surface where the rotor turns.

MANY thanks in advance,

Neal

You can either have it lapped using a stone or using a milling machine on very slow feed to get the best surface finish using a trapaning tool.
Stone ground will be best though.

Lapping is the same as skimming a cylinder head, lye it flat on the bed and then grind/mill it flat. But if your irons are Ok then dont bother.

They are within spec of the handbook, but I' will be using a full rebuild kit with new side seals and everything. I just do'n( like the idea of using new sealing components meeting a 'used' touching surface.

Thanks for the explanation Bucky. Seems like we're both doing similar things ;)

any other info would be highly appreciated

Basically, when you lap the housings, you are removing the nitriding. So, once you have it even from lapping, you need to have it re-nitrided. This is why it usually costs about $70-80 USD per side to have this service done.

Thanks Mahjik... maybe a stupid question, but what kingd of company usually offers this service? I mean, what do they usually do aside from that to make the business work?

Just so I know what kind of companies to look for and contact on my quest to find one locally.

Mazdatrix is who did mine (as well as my porting):

http://www.mazdatrix.com/s.htm

Thanks,

I'll go and look up some values about the debth of nitrating the irons.

A+